Hi Xie,
> Are cctbx and phenix compatible with a 64 bit operating system?
Yes.
> I have Ubuntu 8.04 (64 bit) installed on an Intel Core2 duo system.
Please try the source bundle: cctbx_python_252_bundle.selfx
http://cci.lbl.gov/cctbx_build/
Let me know if there are any problems.
Ralf